A teenager who allegedly brutally beat a girl in Queens was busted last night, law enforcement sources said.

Omer Khogali, 17, of Astoria was in custody in the 114th Precinct and expected to be charged with assault.

He followed the 16-year-old victim into an alley on 43rd Street near 23rd Avenue in Astoria at about 10:45 p.m. Wednesday, and then assaulted her, police said.

The victim was taken to Elmhurst Hospital with serious head injuries.

Sources said the victim and the suspect were seen walking together and then going their separate ways before the attack.